A girl on my local just got the 2010 and said the only difference was the extra padding in the 2011, which you can apparently buy from the company for ~$20.
The only difference is the back boards to make the back of the seats more firm are included with the 2011. They're $8/each through the baby jogger website. I have the 2010 and wouldn't spend the money on the back board or pay extra to have them included with the 2011.
Warning
No formatter is installed for the format bbhtml
The difference between the 2010 and the 2011 is the back board in the seat and an upright strap. The upright strap is pointless; it basically holds the seat in the highest position, which isn't any higher than the regular adjustment strap gets you. I have a 2011 City Mini single and have never used the upright strap. However, it might be useful to just automatically get the seat in the highest position without having to push the kid up and adjust the regular strap; I've just never used it.
The seat back board is important, IMO (I've used both a stroller with and without the back board and find that without it the kids slump a bit more), but you can order the back board from Baby Jogger for $8-10. If I were purchasing one today and found a deal on a 2010 I'd get it and just buy the back boards.
Re: bjcm 2010 or 2011
The difference between the 2010 and the 2011 is the back board in the seat and an upright strap. The upright strap is pointless; it basically holds the seat in the highest position, which isn't any higher than the regular adjustment strap gets you. I have a 2011 City Mini single and have never used the upright strap. However, it might be useful to just automatically get the seat in the highest position without having to push the kid up and adjust the regular strap; I've just never used it.
The seat back board is important, IMO (I've used both a stroller with and without the back board and find that without it the kids slump a bit more), but you can order the back board from Baby Jogger for $8-10. If I were purchasing one today and found a deal on a 2010 I'd get it and just buy the back boards.